The overall objective of this research program is to clarify the role of the brain and endocrine stimuli in the regulation of pulsatile LH release. Specific areas of investigation will include the influence of various CNS areas on pulsatile LH release, the role of neurotransmitters such as serotonin or dopamine in mediating any observed effects, the parameters of pulsatile LH release affected, i.e., LH interpulse interval or LH pulse magnitude, and possible modification of brain serotoninergic function by estrogen.